Journal: Experimental Techniques

Abbreviation

Exp. Tech.

Publisher

Springer

Journal Volumes

ISSN

0732-8818
1747-1567

Description

Filters

2016 - 201912020 - 20222
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Publications 1 - 3 of 3
  • Use of a High-Precision Digital Displacement Encoder for Hybrid Simulation of Seismic Response of Stiff Specimens
    Item type: Journal Article
    Whyte, Catherine; Stojadinovic, Bozidar (2016)
    Experimental Techniques
    Squat reinforced concrete shear walls typically comprise the lateral force resisting system in nuclear facility structures. The geometry and thickness of these walls contribute to an extremely high initial lateral stiffness. When conducting a hybrid simulation, a high stiffness presents a challenge for determining the dynamic response of such walls because very small displacements must be controlled. An extension of the hybrid simulation technique using a digital displacement encoder for high-resolution displacement feedback was developed, implemented, verified, and validated. Then a hybrid model that represents a nuclear facility structure with a large-scale squat wall physical specimen was designed. A ground motion excitation was selected and scaled to represent specific performance levels. These preparations for hybrid simulations of the seismic response of squat shear wall specimens, subjected to different ground motion sequences, are presented to illustrate the new developments. Guidelines are provided for future implementations of feedback instruments for servo-hydraulic systems to conduct hybrid simulation tests.
  • New Frontiers and Innovative Methods for Hybrid Simulation
    Item type: Other Journal Item
    Dyke, Shirley J.; Bursi, Oreste S.; Stojadinovic, Bozidar (2020)
    Experimental Techniques
  • Low-cost Solutions for Velocimetry in Rotating and Opaque Fluid Experiments using Ultrasonic Time of Flight
    Item type: Journal Article
    Burmann, Fabian; Noir, Jérôme André Roland; Beetschen, Stefan; et al. (2022)
    Experimental Techniques
    Many common techniques for flow measurement, such as Particle Image Velocimetry (PIV) or Ultrasonic Doppler Velocimetry (UDV), rely on the presence of reflectors in the fluid. These methods fail to operate when e.g centrifugal or gravitational acceleration leads to a rarefaction of scatterers in the fluid, as for instance in rapidly rotating experiments. In this article we present two low-cost implementations for flow measurement based on the transit time (or Time of Flight) of acoustic waves, that do not require the presence of scatterers in the fluid. We compare our two implementations against UDV in a well controlled experiment with a simple oscillating flow and show we can achieve measurements in the sub-centimeter per second velocity range with an accuracy of ∼ 5 − 10%. We also perform measurements in a rotating experiment with a complex flow structure from which we extract the mean zonal flow, which is in good agreement with theoretical predictions.
Publications 1 - 3 of 3